AMD Sempron 10 Specifications Page 1

Revision Guide forAMD Family 10hProcessors41322Publication # 3.84 Revision:August 2011Issue Date:

10 Conventions41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors<< Shift left first operand by the number of bits specified

100 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors374 Processor Read From L3 Cache May Return Stale DataDescrip

Product Errata 101Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011378 Processor May Operate at Reduced FrequencyDescriptionWhen

102 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors379 DDR3-1333 Configurations with Two DIMMs per Channel May E

Product Errata 103Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011382 L3 Cache Index Disable Cannot Be Modified After L3 Cache

104 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors383 CPU Core May Machine Check When System Software Changes P

Product Errata 105Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011384 DRAM Prefetch May Cause System Hang When Probe Filter is

106 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors385 Processor May Report Incorrect Address For an L3 Cache Er

Product Errata 107Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011386 HyperTransport™ Link in Retry Mode That Receives Repeated

108 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors387 Performance Counters Do Not Accurately Count L3 Cache Evi

Product Errata 109Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011388 L3 Cache Scrubbing Does Not Bypass Disabled L3 Cache Loca

Processor Identification 11Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Processor IdentificationThis section shows how to de

110 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors389 HyperTransport™ Link in Retry Mode May Consume Link Packe

Product Errata 111Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011391 HyperTransport™ Link RTT and RON Specification Violations

112 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors393 Performance Monitor May Count Fastpath Double Operation I

Product Errata 113Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011395 Incorrect Data Masking in Ganged DRAM ModeDescriptionThe

114 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors396 VLDT Maximum Current Specification Exceeded at HyperTrans

Product Errata 115Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011397 VLDT Maximum Current Specification Exceeded on HyperTrans

116 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors398 HyperTransport™ Links In Retry Mode May Experience High B

Product Errata 117Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011399 Memory Clear Initialization May Not Complete if DCT0 Fail

118 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors400 APIC Timer Interrupt Does Not Occur in Processor C-States

Product Errata 119Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011405 HyperTransport™ Link May Fail to Complete TrainingDescrip

12 Processor Identification41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsTable 3. CPUID Values for AMD Family 10h Fr5 (1207)

120 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors406 Processor Does Not Perform BmStsClrOnHltEn FunctionDescri

Product Errata 121Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011407 System May Hang Due to Stalled Probe Data TransferDescrip

122 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors408 Processor AltVID Exit May Cause System HangDescriptionUnd

Product Errata 123Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011411 Processor May Exit Message-Triggered C1E State Without an

124 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors414 Processor May Send Mode Register Set Commands to DDR3 DIM

Product Errata 125Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011415 HLT Instructions That Are Not Intercepted May Cause Syste

126 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors416 DRAM Error Injection May Interfere With Power Management

Product Errata 127Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011417 Processor May Violate Tstab for Registered DDR3-1333 DIMM

128 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors418 Host Mapping of Physical Page Zero May Cause Incorrect Tr

Product Errata 129Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011419 C32r1 Package Processor May Report Incorrect PkgTypeDescr

Processor Identification 13Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 8. CPUID Values for AMD Family 10h AM3 Process

130 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors420 Instruction-Based Sampling Engine May Generate Interrupt

Product Errata 131Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011421 Performance Monitors for Fence Instructions May Increment

132 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors437 L3 Cache Performance Events May Not Reliably Track Proces

Product Errata 133Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011438 Access to MSRC001_0073 C-State Base Address Results in a

134 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors439 DQS Receiver Enable Training May Find Incorrect Delay Val

Product Errata 135Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011440 SMM Save State Host CR3 Value May Be IncorrectDescription

136 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors441 Move from Stack Pointer to Debug or Control Register May

Product Errata 137Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011443 Instruction-Based Sampling May Not Indicate Store Operati

138 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors459 DDR3-1333 Configurations with Three DIMMs per Channel May

Product Errata 139Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011486 Processor Thermal Data Sheet Specification ErrorDescripti

14 Processor Identification41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsMixed Processor Revision SupportAMD Family 10h proce

140 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors521 C1E Resume Failure With Certain Registered DIMM Configura

Product Errata 141Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011550 Latency Performance Counters Are Not AccurateDescriptionL

142 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors610 Processor with Message-Triggered C1E Enabled May Report a

Product Errata 143Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011625 SB-RMI Writes May Not Be Observed by ProcessorDescription

144 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors643 Processor May Increment CPU Watchdog Timer at an Incorrec

Product Errata 145Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011669 Local Vector Table Interrupt May Cause C1E Entry Without

146 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors670 Segment Load May Cause System Hang or Fault After State C

Documentation Support 147Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Documentation SupportThe following documents provide a

Processor Identification 15Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Programming and Displaying the Processor Name String

16 Processor Identification41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors• PkgType[3:0] is from CPUID Fn8000_0001_EBX[31:28].

Processor Identification 17Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 14. String1 Values for Fr2, Fr5 and Fr6 (1207)

18 Processor Identification41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsTable 15. String2 Values for Fr2, Fr5 and Fr6 (1207)

Processor Identification 19Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 16. String1 Values for AM2r2 and AM3 Processor

© 2006-2011 Advanced Micro Devices, Inc. All rights reserved.The contents of this document are provided in connection with Advanced Micro Devices,Inc.

20 Processor Identification41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors1b 01h 1h AMD Athlon(tm) II XLT V - Embedded client2

Processor Identification 21Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 17. String2 Values for AM2r2 and AM3 Processor

22 Processor Identification41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors1b 01h 1h L Processor -2h C Processor -03h 1h L Proc

Processor Identification 23Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 19. String2 Values for S1g3 and S1g4 Processor

24 Processor Identification41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsTable 22. String1 Values for ASB2 ProcessorsPg[0]NC[

Processor Identification 25Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 25. String2 Values for C32r1 ProcessorsPg[0]NC

26 F4x164 Fixed Errata Register41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsF4x164 Fixed Errata RegisterCommunicating the st

MSRC001_0140 OS Visible Work-around MSR0 (OSVW_ID_Length) 27Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011MSRC001_0140 OS Vis

28 MSRC001_0141 OS Visible Work-around MSR1 (OSVW_Status)41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsMSRC001_0141 OS Visibl

MSRC001_0141 OS Visible Work-around MSR1 (OSVW_Status) 29Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 26. Cross Refere

Revision History 3Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Revision History Date Revision DescriptionAugust 2011 3.84 Cl

30 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsProduct ErrataThis section documents product errata for the pr

Product Errata 31Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011279 HyperTransport™ Link RTT and RON Specification Violations

32 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors352 SYSCALL Instruction May Execute Incorrectly Due to Breakpo

Product Errata 33Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011393 Performance Monitor May Count Fastpath Double Operation In

34 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors443 Instruction-Based Sampling May Not Indicate Store Operatio

Product Errata 35Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Tables 28-29 cross-reference the errata to each processor segm

36 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors326 X N/A N/A N/A327 X X X X N/A X X X X X X X X328 X N/A N/A

Product Errata 37Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011391 X X X X N/A X X X X X X X X393 X X X X X X X X X X X X X39

38 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsTable 29. Cross-Reference of Errata to Mobile Processor Segmen

Product Errata 39Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011339 XXX X XXXXXX342 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A343

4 Revision History41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsJanuary 2010 3.66 Added AMD Athlon™ Processor to Tables 7 and

40 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors400 XXX X XXXXXX405 XXX X XXXXXX406 N/A N/A N/A N/A N/A N/A N/

Product Errata 41Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Table 30 cross-references the errata to each package type. An

42 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors338 X N/A N/A N/A N/A X N/A N/A N/A N/A339 XXXXXXXXXX342 X X N

Product Errata 43Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011406 X X407 XXN/AXXXX408 N/A X X N/A X411 X X414 XX XX X415 XXX

44 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors57 Some Data Cache Tag Eviction Errors Are Reported As Snoop E

Product Errata 45Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 201160 Single Machine Check Error May Report OverflowDescriptionA

46 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors77 Long Mode CALLF or JMPF May Fail To Signal GP When Callgate

Product Errata 47Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011178 Default RdPtrInit Value Does Not Provide Sufficient Timing

48 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors244 A DIV Instruction Followed Closely By Other Divide Instruc

Product Errata 49Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011246 Breakpoint Due to An Instruction That Has an Interrupt Sha

Revision History 5Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011November 2008 3.34 Split Table 1 into Tables 2-2 for clarity;

50 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors248 INVLPGA of A Guest Page May Not Invalidate Splintered Page

Product Errata 51Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011254 Internal Resource Livelock Involving Cached TLB ReloadDesc

52 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors260 REP MOVS Instruction May Corrupt Source AddressDescription

Product Errata 53Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011261 Processor May Stall Entering Stop-Grant Due to Pending Dat

54 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors263 Incompatibility With Some DIMMs Due to DQS Duty Cycle Dist

Product Errata 55Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011264 Incorrect DRAM Data Masks Asserted When DRAM Controller Da

56 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors269 ITT Specification Exceeded During Power-Up SequencingDescr

Product Errata 57Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011273 Lane Select Function Is Not Available for Link BIST on 8-B

58 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors274 IDDIO Specification Exceeded During Power-Up SequencingDes

Product Errata 59Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011278 Incorrect Memory Controller Operation In Ganged ModeDescri

6 OverviewRevision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsOverviewThe purpose of th

60 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors279 HyperTransport™ Link RTT and RON Specification ViolationsD

Product Errata 61Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011280 Time Stamp Counter May Yield An Incorrect ValueDescription

62 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors293 Memory Instability After PWROK AssertionDescriptionThe DRA

Product Errata 63Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011295 DRAM Phy Configuration Access FailuresDescriptionUnder a h

64 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors297 Single Machine Check Error May Report OverflowDescriptionA

Product Errata 65Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011298 L2 Eviction May Occur During Processor Operation To Set Ac

66 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors300 Hardware Memory Clear Is Not Supported After Software DRAM

Product Errata 67Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011301 Performance Counters Do Not Accurately Count MFENCE or SFE

68 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors302 MWAIT Power Savings May Not Be Realized when Two or More C

Product Errata 69Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011308 Processor Stall in C1 Low Power StateDescriptionUnder a hi

Overview 7Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011• AMD Phenom II X3 Processor• AMD Phenom II X4 Processor• AMD Phenom

70 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors309 Processor Core May Execute Incorrect Instructions on Concu

Product Errata 71Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011312 CVTSD2SS and CVTPD2PS Instructions May Not Round to ZeroDe

72 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors315 FST and FSTP Instructions May Calculate Operand Address in

Product Errata 73Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011319 Inaccurate Temperature MeasurementDescriptionThe internal

74 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors322 Address and Command Fine Delay Values May Be IncorrectDesc

Product Errata 75Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011326 Misaligned Load Operation May Cause Processor Core HangDes

76 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors327 HyperTransport™ Link RTT Specification ViolationDescriptio

Product Errata 77Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011328 BIST May Report Failures on Initial PowerupDescriptionWhen

78 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors336 Instruction-Based Sampling May Be InaccurateDescriptionThe

Product Errata 79Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011337 CPU Instruction-Based Sampling Fields May Be InaccurateDes

8 Conventions41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h ProcessorsConventionsNumbering• Binary numbers. Binary numbers are indicated

80 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors338 Northbridge Instruction-Based Sampling Fields May Be Inacc

Product Errata 81Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011339 APIC Timer Rollover May Be DelayedDescriptionThe APIC time

82 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors342 SMIs That Are Not Intercepted May Disable InterruptsDescri

Product Errata 83Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011343 Eviction May Occur When Using L2 Cache as General Storage

84 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors344 Intermittent HyperTransport™ Link Training FailuresDescrip

Product Errata 85Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011346 System May Hang if Core Frequency is Even Divisor of North

86 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors348 Processor On-die Termination Resistance is Higher than Spe

Product Errata 87Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011350 DRAM May Fail Training on Cold ResetDescriptionThe DRAM DQ

88 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors351 HyperTransport™ Technology LS2 Low-Power Mode May Not Func

Product Errata 89Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011352 SYSCALL Instruction May Execute Incorrectly Due to Breakpo

Conventions 9Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011• APICXXX: APIC memory-mapped registers; XXX is the byte address o

90 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors353 SYSRET Instruction May Execute Incorrectly Due to Breakpoi

Product Errata 91Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011354 HyperTransport™ Link Training FailureDescriptionSome proce

92 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors355 DRAM Read Errors May Occur at Memory Speeds Higher than DD

Product Errata 93Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011359 MEMCLK is Not Provided for Minimum Specified Time Before C

94 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors360 DRAM CKE and Address Drive Strength Values May Be Incorrec

Product Errata 95Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011361 Breakpoint Due to an Instruction That Has an Interrupt Sha

96 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors362 Illegal Packet on HyperTransport™ Link May Prevent Warm Re

Product Errata 97Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011370 DRAM Read Errors May Occur at DDR2-800 Memory Speeds With

98 Product Errata41322 Rev. 3.84 August 2011Revision Guide for AMD Family 10h Processors372 Processor Read That Matches The Address of an Earlier Unco

Product Errata 99Revision Guide for AMD Family 10h Processors41322 Rev. 3.84 August 2011373 Processor Write to APIC Task Priority Register May Cause E